A small population of SNRs are apparently able to accelerate electrons to much higher energies (\(> 10\)  TeV), sufficient to produce synchrotron radiation at X-ray energies
[1]}, [2]}. G1.9+0.3 also falls into this category, and Figure REF  also shows an image of the remnant that is essentially entirely from nonthermal synchrotron emission. For more details regarding the particle acceleration mechanisms, see the review by [3]}.
